The dynamic loader exists as /usr/lib/Loader.so and is loaded by the
kernel when ET_DYN programs are executed.
The dynamic loader is responsible for loading the dependencies of the
main program, allocating TLS storage, preparing all loaded objects for
execution and finally jumping to the entry of the main program.
This prevents zombies created by multi-threaded applications and brings
our model back to closer to what other OSs do.
This also means that SIGSTOP needs to halt all threads, and SIGCONT needs
to resume those threads.
This changes the Thread::wait_on function to not enable interrupts
upon leaving, which caused some problems with page fault handlers
and in other situations. It may now be called from critical
sections, with interrupts enabled or disabled, and returns to the
same state.
This also requires some fixes to Lock. To aid debugging, a new
define LOCK_DEBUG is added that enables checking for Lock leaks
upon finalization of a Thread.
This commit is a mix of several commits, squashed into one because the
commits before 'Move regex to own Library and fix all the broken stuff'
were not fixable in any elegant way.
The commits are listed below for "historical" purposes:
- AK: Add options/flags and Errors for regular expressions
Flags can be provided for any possible flavour by adding a new scoped enum.
Handling of flags is done by templated Options class and the overloaded
'|' and '&' operators.
- AK: Add Lexer for regular expressions
The lexer parses the input and extracts tokens needed to parse a regular
expression.
- AK: Add regex Parser and PosixExtendedParser
This patchset adds a abstract parser class that can be derived to implement
different parsers. A parser produces bytecode to be executed within the
regex matcher.
- AK: Add regex matcher
This patchset adds an regex matcher based on the principles of the T-REX VM.
The bytecode pruduced by the respective Parser is put into the matcher and
the VM will recursively execute the bytecode according to the available OpCodes.
Possible improvement: the recursion could be replaced by multi threading capabilities.
To match a Regular expression, e.g. for the Posix standard regular expression matcher
use the following API:
```
Pattern<PosixExtendedParser> pattern("^.*$");
auto result = pattern.match("Well, hello friends!\nHello World!"); // Match whole needle
EXPECT(result.count == 1);
EXPECT(result.matches.at(0).view.starts_with("Well"));
EXPECT(result.matches.at(0).view.end() == "!");
result = pattern.match("Well, hello friends!\nHello World!", PosixFlags::Multiline); // Match line by line
EXPECT(result.count == 2);
EXPECT(result.matches.at(0).view == "Well, hello friends!");
EXPECT(result.matches.at(1).view == "Hello World!");
EXPECT(pattern.has_match("Well,....")); // Just check if match without a result, which saves some resources.
```
- AK: Rework regex to work with opcodes objects
This patchsets reworks the matcher to work on a more structured base.
For that an abstract OpCode class and derived classes for the specific
OpCodes have been added. The respective opcode logic is contained in
each respective execute() method.
- AK: Add benchmark for regex
- AK: Some optimization in regex for runtime and memory
- LibRegex: Move regex to own Library and fix all the broken stuff
Now regex works again and grep utility is also in place for testing.
This commit also fixes the use of regex.h in C by making `regex_t`
an opaque (-ish) type, which makes its behaviour consistent between
C and C++ compilers.
Previously, <regex.h> would've blown C compilers up, and even if it
didn't, would've caused a leak in C code, and not in C++ code (due to
the existence of `OwnPtr` inside the struct).
To make this whole ordeal easier to deal with (for now), this pulls the
definitions of `reg*()` into LibRegex.
pros:
- The circular dependency between LibC and LibRegex is broken
- Eaiser to test (without accidentally pulling in the host's libc!)
cons:
- Using any of the regex.h functions will require the user to link -lregex
- The symbols will be missing from libc, which will be a big surprise
down the line (especially with shared libs).
Co-Authored-By: Ali Mohammad Pur <ali.mpfard@gmail.com>
Problem:
- CMake is not outputting `compile_commands.json`.
- `compile_commands.json` is used by build integration tooling such as
`clang-tidy`.
Solution:
- Enable `CMAKE_EXPORT_COMPILE_COMMANDS` option so that the file is
output.
This is our first client of the new JSON GUI declaration thingy.
The skeleton of the TextEditor app GUI is now declared separately from
the C++ logic, and we use the Core::Object::name() of widgets to locate
them once they have been instantiated by the GUI builder.
I know, the tags don't actually matter. However, clang warns by default,
and instead of disabling the warning for clang I'd rather enable the warning
for gcc.
Concludes #3096.
Phew! From here on, build system and CI will ensure that all new code
defines compilation-unit-only code as 'static', and that dead code can
be found more easily. Also, this style encourages type checking
by suggesting that you put a proper declaration in a shared header.
It looks like PR #2986 mistakenly removed this from both the
Clang and GCC CXX_FLAGS, when the intention seems to have been
to only disable it for Clang.
Useful for sanitizer fuzzer builds.
clang doesn't have a -fconcepts switch (I'm guessing it just enables
concepts automatically with -std=c++2a, but I haven't checked),
and at least the version on my system doesn't understand
-Wno-deprecated-move, so pass these two flags only to gcc.
In return, disable -Woverloaded-virtual which fires in many places.
The preceding commits fixed the handful of -Wunused-private-field
warnings that clang emitted.
After running a build command, make by default stat()s the command's
output, and if it wasn't touched, then it cancels all build steps
that were scheduled only because this command was expected to change
the output.
Ninja has the same feature, but it's opt-in behind the per-command
"restat = 1" setting. However, CMake enables it by default for all
custom commands.
Use Meta/write-only-on-difference.sh to write the output to a temporary
file, and then copy the temporary file only to the final location if the
contents of the output have changed since last time.
write-only-on-difference.sh automatically creates the output's parent
directory, so stop doing that in CMake.
Reduces the number of build steps that run after touching a file
in LibCore from 522 to 312.
Since we now no longer trigger the CMake special case "If COMMAND
specifies an executable target name (created by the add_executable()
command), it will automatically be replaced by the location of the
executable created at build time", we now need to use qualified paths to
the generators.
Somewhat related to #2877.
Seems like we can build without these two flags now:
-Wno-sized-deallocation
-fno-sized-deallocation
I don't remember why they were needed in the first place.
This allows us to look up source file/line information from addresses
without bloating the build too much. It could probably be made smaller
with some tricks.
I tried setting it to Release, then noticed that it didn't build
due to gcc's optimizer-level dependent warnings and -Werror, then
started fixing the warnings for a bit (all false positives),
then looked at the global CMakeLists.txt and realized that the
default build is aleady using compiler optimizations. It looks like
people aren't supposed to change this, so make that explicit to
be friendly to people familiar with cmake but new to serenity.
The SDL port failed to build because the CMake toolchain filed pointed
to the old root. Now the toolchain file assumes that the Root is in
Build/Root.
Additionally, the AK/ and Kernel/ headers need to be installed in the
root too.
Make sure that userspace is always referencing "system" headers in a way
that would build on target :). This means removing the explicit
include_directories of Libraries/LibC in favor of having it export its
headers as SYSTEM. Also remove a redundant include_directories of
Libraries in the 'serenity build' part of the build script. It's already
set at the top.
This causes issues for the Kernel, and for crt0.o. These special cases
are handled individually.
